The Utilities Committee met 01/07/2025. The item that took up most of the meeting was an overview and discussion of the costs related to the biosolids composting program run by the city. In short, regarding composting, Utilities Director Chris Stempa told the committee, “I would not recommend doing it for the cost perspective.”
I’ve prepared a transcript of the discussion for download:
Director Stempa has been working on the sludge composting program since he first joined the city in 2007. He told the committee, “From a cost perspective, I struggle mightily with it, and I love composting.” Composting accounted for 12% of the biosolids management program but only 5% of overall production. Composting costs averaged out to $66.79 per wet ton as compared to the costs related to standard landfill application which averaged out to only $17.87 per wet ton.
Additionally, from a green standpoint, carbon emissions were very similar for each process. Director Stempa included a snippet of a never completed report that they had started preparing back in 2018-2019 when they were contemplating building a large-scale compost facility. At the time, annual CO2 emissions for composting had been estimated at 47,226 metric tons as compared to 52,255 for land application of biosolids. Director Stempa noted that those 2018-2019 figures underestimated emissions related to composting because they assumed there were no transportation costs associated with composting, when in fact there were.
The city’s current compost program is located at the Outagamie County landfill, but the landfill needs to expand and is looking at taking over the area where the composting program is currently run. If the city were to build a large-scale composting facility the actual cost of construction would be over $6 million, and there would, of course, be the question of where to locate it because “Nobody wants it in their backyard.”
Additionally, there were many regulatory issues and hurdles associated with building and operating a facility. Director Stempa noted that as part of the wastewater treatment plant’s sludge storage building project, they had initially wanted to install an additional concrete pad that would have been able to serve as the foundation for a future bio solids composting building, “But we could not get regulatory approval because it would have been one of the first in the state. And there’s all these setbacks that are codified, and we would have had to work through the attorney’s office, city planning, public works, and there just was not enough time to do that. And first and foremost, we never got a response on time.”
For all of those reasons, staff was looking at 2025 being the last year of the biosolids composting program.
Alderperson Patrick Hayden (District 7), in response to the comments about regulatory hurdles, mentioned that the political climate in Madison was changing and said, “[M]aybe it’s worth one last swing to see if we could get regulations there, because there’s a record number of representatives in the Senate and […] the Assembly in Madison from Appleton. So, it seems like we would be—they would be more likely to work with the city and represent our interest than they have in the past decade.”
Director Stempa believed it would still be a financially difficult venture that took up staff resources and time. Additionally, there were still a lot of regulatory unknowns on contaminants. “I’m still feeling that not only in the on the wastewater effluent side but the drinking water side. And so, there’s no assurances that you’d commit to this, large or small scale, that that that needle might move in terms of what you can do with it. And if people don’t want to buy it or put it on their gardens, or put it on their on their on their golf course, what are you going to do with it? And I can, I can tell you, Milwaukee dealt with that for more than one year of—um, they do not sell everything. And so that is not—I don’t want to speak to the economics because I don’t know it for sure, but I know when they were going through the PCB incident, that was a tough time for them to find home for—find a home for that material. So, I’m not saying it’s not worth looking at. I just—I’m really reluctant.”
The item appeared on the agenda as an information item, so no action was taken. It was just the beginning of discussions on the issue and it sounded like it would be coming back in front of the committee again at some point in the future.
View full meeting details and video here: https://cityofappleton.legistar.com/MeetingDetail.aspx?ID=1269085&GUID=46DEAF50-8AB2-441D-AD15-8253A80CFA74
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